/* Copyright (c) 2020 XEPIC Corporation Limited */
/*
 * Copyright (c) 2003-2010 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

#include "stringheap.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "ivl_alloc.h"
#include "sys_priv.h"

struct stringheap_cell {
  struct stringheap_cell *next;
};

#define PAGE_SIZE 8192
#define STRINGHEAP_SIZE (PAGE_SIZE - sizeof(struct stringheap_cell))

const char *strdup_sh(struct stringheap_s *hp, const char *txt) {
  char *res;
  unsigned len = strlen(txt);
  assert(len < STRINGHEAP_SIZE);

  if (hp->cell_lst == 0) {
    hp->cell_lst = malloc(PAGE_SIZE);
    hp->cell_lst->next = 0;
    hp->cell_off = 0;
  }

  if ((STRINGHEAP_SIZE - hp->cell_off - 1) <= len) {
    struct stringheap_cell *tmp = malloc(PAGE_SIZE);
    tmp->next = hp->cell_lst;
    hp->cell_lst = tmp;
    hp->cell_off = 0;
  }

  res = (char *)(hp->cell_lst + 1);
  res += hp->cell_off;
  strcpy(res, txt);
  hp->cell_off += len + 1;

  return res;
}

void string_heap_delete(struct stringheap_s *hp) {
  struct stringheap_cell *cur, *tmp;

  for (cur = hp->cell_lst; cur; cur = tmp) {
    tmp = cur->next;
    free((char *)cur);
  }
  hp->cell_lst = 0;
  hp->cell_off = 0;
}
